I've been in some Senate offices, very minimal in size There's room for a desk, a bookcase and couple of chairs, not spacious at all.
I haven't seen the House offices, but they're probably even smaller. It's impossible to believe she was overlooked, or fell down and hit her head. I doubt there's adequate room to fatally "fall down"...unless she was up on a ladder or something (not credible)
The incident occurred in a district office in Florida, not in the Capitol. Scarborough was not in town at the time.